135 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			135 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * BTRFS filesystem implementation for U-Boot
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|  *
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|  * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
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|  */
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| 
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| #include "btrfs.h"
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| #include <linux/lzo.h>
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| #include <u-boot/zlib.h>
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| #include <asm/unaligned.h>
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| 
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| static u32 decompress_lzo(const u8 *cbuf, u32 clen, u8 *dbuf, u32 dlen)
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| {
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| 	u32 tot_len, in_len, res;
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| 	size_t out_len;
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| 	int ret;
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| 
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| 	if (clen < 4)
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| 		return -1;
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| 
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| 	tot_len = le32_to_cpu(get_unaligned((u32 *)cbuf));
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| 	cbuf += 4;
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| 	clen -= 4;
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| 	tot_len -= 4;
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| 
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| 	if (tot_len == 0 && dlen)
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| 		return -1;
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| 	if (tot_len < 4)
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| 		return -1;
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| 
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| 	res = 0;
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| 
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| 	while (tot_len > 4) {
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| 		in_len = le32_to_cpu(get_unaligned((u32 *)cbuf));
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| 		cbuf += 4;
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| 		clen -= 4;
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| 
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| 		if (in_len > clen || tot_len < 4 + in_len)
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| 			return -1;
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| 
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| 		tot_len -= 4 + in_len;
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| 
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| 		out_len = dlen;
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| 		ret = lzo1x_decompress_safe(cbuf, in_len, dbuf, &out_len);
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| 		if (ret != LZO_E_OK)
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| 			return -1;
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| 
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| 		cbuf += in_len;
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| 		clen -= in_len;
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| 		dbuf += out_len;
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| 		dlen -= out_len;
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| 
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| 		res += out_len;
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| 	}
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| 
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| 	return res;
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| }
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| 
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| /* from zutil.h */
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| #define PRESET_DICT 0x20
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| 
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| static u32 decompress_zlib(const u8 *_cbuf, u32 clen, u8 *dbuf, u32 dlen)
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| {
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| 	int wbits = MAX_WBITS, ret = -1;
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| 	z_stream stream;
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| 	u8 *cbuf;
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| 	u32 res;
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| 
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| 	memset(&stream, 0, sizeof(stream));
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| 
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| 	cbuf = (u8 *) _cbuf;
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| 
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| 	stream.total_in = 0;
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| 
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| 	stream.next_out = dbuf;
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| 	stream.avail_out = dlen;
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| 	stream.total_out = 0;
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| 
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| 	/* skip adler32 check if deflate and no dictionary */
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| 	if (clen > 2 && !(cbuf[1] & PRESET_DICT) &&
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| 	    ((cbuf[0] & 0x0f) == Z_DEFLATED) &&
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| 	    !(((cbuf[0] << 8) + cbuf[1]) % 31)) {
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| 		wbits = -((cbuf[0] >> 4) + 8);
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| 		cbuf += 2;
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| 		clen -= 2;
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| 	}
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| 
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| 	if (Z_OK != inflateInit2(&stream, wbits))
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| 		return -1;
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| 
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| 	while (stream.total_in < clen) {
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| 		stream.next_in = cbuf + stream.total_in;
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| 		stream.avail_in = min((u32) (clen - stream.total_in),
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| 				      (u32) btrfs_info.sb.sectorsize);
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| 
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| 		ret = inflate(&stream, Z_NO_FLUSH);
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| 		if (ret != Z_OK)
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| 			break;
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| 	}
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| 
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| 	res = stream.total_out;
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| 	inflateEnd(&stream);
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| 
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| 	if (ret != Z_STREAM_END)
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| 		return -1;
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| 
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| 	return res;
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| }
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| 
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| u32 btrfs_decompress(u8 type, const char *c, u32 clen, char *d, u32 dlen)
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| {
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| 	u32 res;
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| 	const u8 *cbuf;
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| 	u8 *dbuf;
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| 
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| 	cbuf = (const u8 *) c;
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| 	dbuf = (u8 *) d;
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| 
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| 	switch (type) {
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| 	case BTRFS_COMPRESS_NONE:
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| 		res = dlen < clen ? dlen : clen;
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| 		memcpy(dbuf, cbuf, res);
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| 		return res;
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| 	case BTRFS_COMPRESS_ZLIB:
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| 		return decompress_zlib(cbuf, clen, dbuf, dlen);
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| 	case BTRFS_COMPRESS_LZO:
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| 		return decompress_lzo(cbuf, clen, dbuf, dlen);
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| 	default:
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| 		printf("%s: Unsupported compression in extent: %i\n", __func__,
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| 		       type);
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| 		return -1;
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| 	}
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| }
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